The simple answer is no, there is no particularly good way to access the Anarki REPL in DrRacket at the moment.
There is a `#lang anarki`, but as far as I know nobody has used it yet. I only gave it a minimal amount of support to make it possible to use Anarki to write modules Racket code could (require ...), and I didn't pay any attention to DrRacket.
I recommend ignoring `#lang anarki` for now, because it might be subject to change as we figure out more of what things like DrRacket need from it.
- It seems it might be some difference depending on whether the account you're doing this with is roaming or an administrator. At least, a lot of people in the thread thought it would make a difference. Maybe your command prompt works with Arc because it's a different user.
If you find out any more about what's going on, I hope you'll keep us in the loop. :)
Of course, since you already have this working via the command prompt, it's understandable if you prefer not to mess with it.